Astronomy Is Written For Astronomers

First Of All, We Must Note That The Universe Is Spherical.

The Two Revolutions, I Mean The Annual Revolutions Of The Declination And Of The Centre Of The Earth, Are Not Completely Equal; That Is The Return Of The Declination To Its Original Value Is Slightly Ahead Of The Period Of The Centre. Hence It Necessarily Follows That The Equinoxes And Solstices Seem To Anticipate Their Timing, Not Because The Sphere Of The Fixed Stars Moves To The East, But Rather The Equatorial Circle Moves To The West, Being At An Angle To The Plane Of The Ecliptic In Proportion To The Declination Of The Axis Of The Terrestrial Globe.

To Know That We Know What We Know, And To Know That We Do Not Know What We Do Not Know, That Is True Knowledge.

If There Be Some Who, Though Ignorant Of All Mathematics . . . Dare To Reprove This Work, Because Of Some Passage Of Scripture, Which They Have Miserably Warped To Their Purpose, I Regard Them Not, And Even Despise Their Rash Judgement.

Moreover, Since The Sun Remains Stationary, Whatever Appears As A Motion Of The Sun Is Really Due Rather To The Motion Of The Earth.